Well, being as Instantiate only creates an instance of one object at a time I’m not sure there is a way to make a group of objects without some sort of a repeat loop like you’re using. Is there a reason the technique you cited isn’t acceptable?
If you just remove the yield it will spawn them all at the same time. Then you just need to spread the position a bit around so that they wont all spawn at the exact same position. You can use the Random class for that.
Thanks for the advise! yes i was thinking to make few prefab, but just wondering if its able to script it so it looks more tidy, maybe i can try using the random class.